The recent good news out of One Madison Park?that Related is settling the remaining claims at the troubled project building and relaunching sales later this year?may already be benefiting one building resident. Peter Buffett, musician and son of Warren Buffett, listed his 3BR, 3BA place on the 18th floor in early March. It has just gone into contract. No word on the sale price yet, but Buffett paid $3,563,875 for it in 2009 and was asking $4.1 million. It was One Madison Park's only active listing.